1. Field of the Invention
The present invention relates to a laser radar driving apparatus provided for laser radar mounted, for example, on automobiles to measure a distance to a target object.
2. Description of the Related Art
Laser radar is considered to oscillate laser beams and detect the laser beams to measure a direction of and a distance to a target object, for example. Laser is an abbreviation of “light amplification by stimulated emission of radiation”. A conventional technology related to the laser radar is shown in, for example, preceding vehicle detection device and control method thereof that detects a preceding vehicle ahead of the own vehicle with the use of a scanning laser radar (see, e.g., Japanese Patent Application Laid-Open Publication No. 2005-181114 (page 3, FIGS. 1 to 10)).
Laser radar driving apparatuses include, for example, a laser radar driving apparatus that has a movable unit including a lens, which allows a laser beam to pass therethrough, moved in the lateral direction or longitudinal direction, which is a so-called lens shift type laser radar driving apparatus (not shown).
Another laser radar driving apparatus has conceived as a laser radar driving apparatus, for example, having a movable unit that includes an optical member to which a laser beam is applied and that is driven with being supported by a plurality of suspension wires, which is a so-called suspension support type laser radar driving apparatus (not shown).
Recently, it has been requested in the market to further improve response characteristics such as angular acceleration sensitivity in the lens shift type laser radar driving apparatuses and the suspension support type laser radar driving apparatuses.
It has been also requested in the market to lower the prices of the lens shift type laser radar driving apparatuses and the suspension support type laser radar driving apparatuses.
Therefore, for example, a suspension support type laser radar driving apparatus is conceived, which has a price lowered by omitting a servo drive control function. A servo or servo mechanism means a mechanism measuring a state of an object to be controlled and comparing the measurement result with a reference value to cause correction control to be automatically executed.
However, in laser radar driving apparatuses using the above conventional movable unit support system as the suspension support system, if the servo was not used for the drive control, it has been difficult to execute the accurate drive control of the movable unit and to achieve improvement in the response characteristics.